﻿//  Copyright 2019 Google Inc. All Rights Reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.

namespace NtCoreLib.Ndr.Marshal;

#pragma warning disable 1591
/// <summary>
/// NDR integer representation.
/// </summary>
public enum NdrIntegerRepresentation
{
    LittleEndian,
    BigEndian
}

/// <summary>
/// NDR character representation.
/// </summary>
public enum NdrCharacterRepresentation
{
    ASCII = 0,
    EBCDIC
}

/// <summary>
/// NDR floating point representation.
/// </summary>
public enum NdrFloatingPointRepresentation
{
    IEEE = 0,
    VAX,
    Cray,
    IBM
}

/// <summary>
/// Definition of the NDR data representation for an NDR stream.
/// </summary>
public struct NdrDataRepresentation
{
    /// <summary>
    /// The integer representation of the NDR data.
    /// </summary>
    public NdrIntegerRepresentation IntegerRepresentation { get; set; }
    /// <summary>
    /// The character representation of the NDR data.
    /// </summary>
    public NdrCharacterRepresentation CharacterRepresentation { get; set; }
    /// <summary>
    /// The floating representation of the NDR data.
    /// </summary>
    public NdrFloatingPointRepresentation FloatingPointRepresentation { get; set; }

    internal NdrDataRepresentation(byte[] data_rep)
    {
        CharacterRepresentation = (NdrCharacterRepresentation)(data_rep[0] & 0xF);
        IntegerRepresentation = (data_rep[0] & 0xF0) == 0 ? NdrIntegerRepresentation.BigEndian : NdrIntegerRepresentation.LittleEndian;
        FloatingPointRepresentation = (NdrFloatingPointRepresentation)data_rep[1];
    }

    internal byte[] ToArray()
    {
        byte[] ret = new byte[4];
        ret[0] = (byte)(IntegerRepresentation == NdrIntegerRepresentation.LittleEndian ? 0x10 : 0);
        ret[0] |= (byte)CharacterRepresentation;
        ret[1] = (byte)FloatingPointRepresentation;
        return ret;
    }
}
#pragma warning restore 1591

